User interface for a portion of a display screen



FIG. 1 is a front view of a user interface for a portion of a display screen showing my new design;

FIG. 2 is an enlarged view of the region in FIG. 1;

FIG. 3 is a front view of another user interface for a portion of a display screen showing an alternative embodiment thereof; and,

FIG. 4 is an enlarged view of the region in FIG. 3.

The broken line showing of various regions forms no part of the claimed design. The broken line showing of the remainder of the window and the display screen is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a user interface for a portion of a display screen, as shown and described. 